Now we have 3 different NFT Standard proposals: #30 , #37 , #41 .
We need to choose one to accept.

@lightszero I have some questions for you to answer.

1. As a Non-fungible Token Standard, why we need totalSupply? Since each token is not the same, there should be no need to count the number of tokens?

2. In the case of a transfer, if we know the nftid, we can get the owner of it. So there's no need to provide the from parameter for transfer?

3. What is the purpose of getTXInfo?